This study investigated the effectiveness of novel and innovative pretreatments (NIP) using thermoultrasound and microwave-mediated freeze-thaw (TSFT, MWFT) for improving the mid-infrared drying of dragon fruit, as compared with recent pretreatment methods using cold plasma (CP), ultrasound (US), edible coating (EC), microwave and infrared blanching (MWB, IRB). Except for EC, all selected pretreatment methods induced ultrastructural changes, resulting in accelerated moisture removal and reduced drying time. In addition, all the pretreatments also induced modifications in colour, structure, and texture, with NIP demonstrating superior outcomes for colour, rehydration, shrinkage, and hardness properties. Blanching pretreatments (MWB and IRB) improved phytochemical and antioxidant properties, including total phenolics, betacyanin, betaxanthin, CUPRAC, hydroxyl radical scavenging, and ABTS, except for ascorbic acid, which was better preserved by TSFT. The study underscores the time-saving and quality enhancement advantage of NIP, over other recent methods for improving mid-infrared drying.
To meet the requirements of biomedical applications in the antibacterial realm, it is of great importance to explore nano-antibiotics for wound disinfection that can prevent the development of drug resistance and possess outstanding biocompatibility. Therefore, we attempted to synthesize an atomically dispersed ion (Fe) on phenolic carbon quantum dots (CQDs) combined with an organic photothermal agent (PTA) (Fe@SAC CQDs/PTA) via a hydrothermal/ultrasound method. Fe@SAC CQDs adequately exerted peroxidase-like activity while the PTA presented excellent photothermal conversion capability, which provided enormous potential in antibacterial applications. Based on our work, Fe@SAC CQDs/PTA exhibited excellent eradication of Escherichia coli (>99% inactivation efficiency) and Staphylococcus aureus (>99% inactivation efficiency) based on synergistic chemodynamic therapy (CDT) and photothermal therapy (PTT). Moreover, in vitro experiments demonstrated that Fe@SAC CQDs/PTA could inhibit microbial growth and promote bacterial biofilm destruction. In vivo experiments suggested that Fe@SAC CQDs/PTA-mediated synergistic CDT and PTT exhibited great promotion to wound disinfection and recovery effects. This work indicated that Fe@SAC CQDs/PTA could serve as a broad-spectrum antimicrobial nano-antibiotic, which was simultaneously beneficial for bacterial biofilm eradication, wound disinfection, and wound healing.